1. Field of the Invention
The present invention relates generally to a portable electronic apparatus, and more particularly to the structure and arrangement of control parts on a casing of a portable electronic apparatus.
2. Description of Related Art
A variety of control members such as a push button, a slide switch and a rotary dial are used for control parts of a portable electronic apparatus such as an electronic camera and a personal digital assistant (PDA). The size and operability of the portable electronic apparatus depend on what types of control parts are used and how they are arranged on a casing of the portable electronic apparatus.
In particular, as the portable electronic apparatus has recently become smaller and has had more functions, it is important to secure a space for the control parts and improve the operability in the development of the apparatus.
In view of the foregoing, it is an object of the present invention to provide a portable electronic apparatus whose control parts are concentrated, and which can be operated easily by one hand.
To achieve the above-mentioned object, the present invention is directed to a portable electronic apparatus comprising: a casing; a dial control part for selecting a mode among a plurality of modes of the portable electronic apparatus; and a cross key control part for performing at least one of selecting an item in the mode selected by the dial control part and entering a command; wherein the dial control part is arranged on the casing at such a position as to be operated by a thumb of a hand holding a part of the casing, and the cross key control part is arranged on the casing close to the dial control part, at such a position as to be operated by the thumb.
According to the present invention, it is possible to select a mode only by rotating the dial control part by the thumb of one hand holding the apparatus. It is also possible to easily operate the cross key control part only by shifting the thumb from the dial control part. The cross key control part may comprise a button member capable of tilting upward, downward, rightward, and leftward.
The dial control part preferably has a concave part at a center of a face thereof, whereby the dial control part can also be used as a thumb rest, the thumb being placed securely on the concave part while the dial control part is not operated. Thus, there is no necessity of securing a special space for the thumb rest. Moreover, the thumb can be placed securely on the concave part at the center of the dial.
Preferably, the portable electronic apparatus further comprises an execution button for fixing the item selected by the cross key control part, the execution button being arranged on the casing at such a position as to be operated by the thumb and at an opposite side of the dial control part across the cross key control part. Since the dial control part, the cross key control part and the execution button are arranged side by side in that order, it is possible to perform a sequence of operations by moving the thumb efficiently. The mode is selected by the dial control part, the detailed settings are selectively entered by the cross key control part, and the settings are fixed by the execution button.
For example, the portable electronic apparatus further comprises: an imaging device for converting a light from a subject into image data; a storage medium interface for recording the image data obtained by the imaging device into an external storage medium, and for reading data recorded in the external storage medium; and a flat display for displaying at least one of an image represented by the image data obtained by the imaging device and an image represented by the data read from the external storage medium. That is, the portable electronic apparatus may be an electronic camera.